Design of molecularly imprinted polymer materials relying on hydrophobic interactions

The design of molecularly imprinted polymers (MIPs) for the specific binding of hydrophobic molecules (mitotane) was investigated by considering monomers and cross-linking agents with variable hydrophobic character, methyl methacrylate, butyl methacrylate and lauryl methacrylate as functional monomers, and ethylene glycol dimethacrylate and 1,6-hexanediol dimethacrylate as cross-linking agents. MIPs were bound to a porous silica support by means of a radical transfer reaction with grafted 3-mercaptopropyl groups. Equilibrium adsorption isotherms to molecularly imprinted and non-imprinted materials were modeled with the Volmer and Langmuir-Volmer isotherms, giving the thermodynamic parameters of adsorption. The most hydrophobic monomer provided the highest selective adsorption although strong non-selective adsorption and the intrinsic softness of poly(lauryl methacrylate) is detrimental to selectivity. Adsorption was exothermic with a predominant enthalpic contribution. Adsorption kinetics were fast due to the high accessibility of molecular imprints on the surface of the thin MIP layer coating the porous silica support.

Automated summary

The design of molecularly imprinted polymers (MIPs) for specific binding of hydrophobic molecules was investigated in this study. The results showed that the most hydrophobic monomer provided the highest selective adsorption, but the non-selective adsorption and softness of poly(lauryl methacrylate) had a negative impact on selectivity. The adsorption process was exothermic and had fast kinetics.